Gazebo | Ignition | Community
Ask Your Question

Revision history [back]

click to hide/show revision 1
initial version

Manipulator initial position altered after changing from a position_controllers/JointTrajectoryController to a effort_controllers/JointTrajectoryController

Hi, I am currently on ROS Kinetic, working on the integration of a Husky and a Robotis Manipulator-H. Right now I have the manipulator working with MoveIt! while standing fixed on top of a Husky robot, all simulated in Gazebo. First of all I was having a problem which was the fact that when I moved the Husky robot (for example, with the teleop keyboard), his dynamics were not correct, i. .e, the front wheels would lift up when I moved him forward and the back wheels would also lift up If I moved him backwards. I research about the possible reasons why this was happening and via this link:

http://answers.gazebosim.org/question/15045/why-my-model-seems-to-defy-the-gravity-and-seems-to-be-grabbed-from-the-top-when-moving/#18851

I found out that the fact that I was using a position_controllers/JointTrajectoryController (from the "controller_manager" package) to control the manipulator (via MoveIt!) was afecting my robot's dynamics. The solution was changing this controller to a effort_controllers/JointTrajectoryController (also from the "controller_manager"), which made it possible to move my robot around normally. The only problem is that now, the initial position of the manipulator is a bit odd. The following images show the normal position of the manipulator (when using a position_controllers/JointTrajectoryController) and the position of the manipulator when using a effort_controllers/JointTrajectoryController:

Normal position, when using a position_controllers/JointTrajectoryController: C:\fakepath\Normal_position.png

Altered position, when using a effort_controllers/JointTrajectoryController: C:\fakepath\Altered_position.png

Besides this initial position problem, path planning has equally good (or even perfect) results when using both controller types. Has this initial position any side effect in my system/manipulator/simulation?

Thanks in advance!

P.S.: This post was originated from the previous created by me in GitHub: https://github.com/znbrito/Brito-thesis-Robotis-Manipulator-H-path-planning/issues/3

Manipulator initial position altered after changing from a position_controllers/JointTrajectoryController to a effort_controllers/JointTrajectoryController

Hi, I am currently on ROS Kinetic, working on the integration of a Husky and a Robotis Manipulator-H. Right now I have the manipulator working with MoveIt! while standing fixed on top of a Husky robot, all simulated in Gazebo. First of all I was having a problem which was the fact that when I moved the Husky robot (for example, with the teleop keyboard), his dynamics were not correct, i. .e, the front wheels would lift up when I moved him forward and the back wheels would also lift up If I moved him backwards. I research about the possible reasons why this was happening and via this link:

http://answers.gazebosim.org/question/15045/why-my-model-seems-to-defy-the-gravity-and-seems-to-be-grabbed-from-the-top-when-moving/#18851

I found out that the fact that I was using a position_controllers/JointTrajectoryController (from the "controller_manager" package) to control the manipulator (via MoveIt!) was afecting my robot's dynamics. The solution was changing this controller to a effort_controllers/JointTrajectoryController (also from the "controller_manager"), which made it possible to move my robot around normally. The only problem is that now, the initial position of the manipulator is a bit odd. The following images show the normal position of the manipulator (when using a position_controllers/JointTrajectoryController) and the position of the manipulator when using a effort_controllers/JointTrajectoryController:

Normal position, when using a position_controllers/JointTrajectoryController: C:\fakepath\Normal_position.png

Altered position, when using a effort_controllers/JointTrajectoryController: C:\fakepath\Altered_position.png

Besides this initial position problem, path planning has equally good (or even perfect) results when using both controller types. Has this initial position any side effect in my system/manipulator/simulation?

Thanks in advance!

P.S.: This post was originated from the previous created by me in GitHub: https://github.com/znbrito/Brito-thesis-Robotis-Manipulator-H-path-planning/issues/3